In what amounted to arguably, perhaps the most over the top hour ever on television Bea Arthur starred in this musical review featuring Rock Hudson, Melba Moore and the risque Madame. They performed numbers, like the one below, did some wacky comedy and changed clothes a lot. There are quite a few clips available on YouTube, though the show is obscure enough to have been overlooked by IMDB.
Here, the entire ensemble shares the gospel with an appreciative crowd. This show has never made it to commercial DVD, though you can get unofficial versions on sites like iOffer.com.
Obscurity factor: 10 (not on DVD, available in parts on YouTube, not even on IMDB)